The Formula for Change
by Mostly Charmless
Summary: Four years after the Snap, Bruce Banner tries to find his place in the world and understand his purpose in life. Instead, he meets a girl and joins a book club. Update - Chapter Four: Synchronizing Brainwaves
1. One: Kinetic Energy

**Author's Note:** What to say? I'm a long-time lurker of fanfiction sites, but I've never posted anything before. So I guess I'm writing a romance about Endgame Hulk. Because why the hell not. Enjoy?

* * *

**The Formula for Change**

One: Kinetic Energy

"Oh, please pick up, please pick up, please pick up," Tegan whispered over and over into her phone as the car pulled out onto Washington Street and proceeded in the direction of Boston's North End.

Beside her in the driver's seat, Benjamin Goodall gave her an exasperated look. "Stop worrying, we're only ten minutes late," he told her.

She waved her hand to shush him. After a moment, she heard a voice in her ear: "_Brown Butter Bakery, how may I help you?_"

"Yes, hello, this is Tegan Thomas," she said quickly, silently thanking whichever divine being had answered her prayers. "My fiancé and I have an appointment at eleven A.M. for a cake tasting, and we're going to be a little late. We're on our way, though, so please don't give away our time."

"_Not a problem, Ms. Thomas. We'll see you when you get here._"

"Thank you so much! And sorry!" She jabbed the 'End' button and tossed her phone into her purse, pressing the heels of her palms into her eyes. "Crap on a cracker."

"Would you relax?" said Benjamin, peeved. "They're not going to give our appointment to someone else."

"Why wouldn't they?" Tegan retorted. "We're not exactly reliable customers. We've already cancelled on them twice now. Frankly, I'm shocked that they still want our business."

Ben rolled his eyes. "It's just cake, Tegan. It doesn't have to be anything fancy. I don't know why we can't just get a couple of sheet cakes from the bakery section at Crosby's."

Tegan stared at him blankly, not sure she had heard him correctly.

"What?" he said.

"That is literally what I suggested. _You're_ the one who said sheet cakes were tacky."

His brow wrinkled as he stared out at the road. "I never said that," he replied.

"Those were your exact words!"

Ben shook his head as he turned the car onto State Street. "Don't bite my head off for saying this, Tegan, but I'm kind of worried about you. You seem really stressed, and I think it might be taking a toll on your mental health."

Tegan took a deep breath, trying to remain calm. This was not the time to get into another argument. "I realize I'm stressed," she answered evenly. "I've had a lot on my plate. I just took on a bunch of new clients, my landlord is dragging his ass about my broken oven, and my mom is on my case because we still haven't sent out the invitations."

"Your mom... means well," said Ben slowly. "But it's not her wedding. It's ours."

The words were out of her mouth before she could stop herself: "Is it?"

For a long moment Ben was quiet. "What the hell is that supposed to mean?" he finally asked in a low voice.

Tegan sighed, suddenly tired. "It means I'm frustrated, Ben. I feel like I've been planning a wedding by myself for the past three months. I know you're busy, but so am I. And yet I've found the time to book the venue and the caterer, find the dress and the tux, order the flowers, make the party favors. I even made the decorations for the tables, from crap I found at the craft store. You could have helped at any point, but you haven't lifted a finger."

"I haven't helped because it didn't seem like you _wanted_ my help," Ben fired back angrily. "I have offered so many suggestions, Tegan, and you shot them all down."

"What suggestions have you made? Name one."

"I can't remember any right now! Not when you're putting me on the spot like this!"

Tegan bit her lip hard. _Every damn time,_ she thought to herself. She could never win. "The only thing I've asked you to do is make a list of the people you want to invite to the reception. And you haven't even done that."

"Because I don't care!" he shouted, pounding the steering wheel with his fist.

Tegan stared at him, taken aback. "What do you mean?" she asked, her voice wavering. "What don't you care about?"

"Any of it! The cake, the guests, the frigging party favors! It doesn't matter! None of it matters!"

In the silence that followed, Tegan's vision grew blurry as she stared out the windshield. Her stomach felt like it was twisted into knots, and she was aware that she had stopped breathing. If she had been in a more objective frame of mind, it would have occurred to her that she was getting used to the sensation.

"Do I matter?" she whispered.

Without warning the car was thrown violently sideways as its passenger side was struck by an SUV driven at full speed. The vehicle spun in a circle, bouncing off of two more cars before skidding to a halt in the middle of the intersection.

For what seemed like hours, Tegan couldn't bring herself to move. Her head was pounding, her ears ringing, and her neck and shoulder were screaming in pain. She thought she had gone blind, until she realized her eyes were squeezed shut. With an effort, she opened them.

The air was thick with smoke and some kind of dust. She could hardly see through it. As the ringing in her ears faded, she could hear screeching tires, frenzied honking, people screaming.

She licked her lips and tasted blood. "Ben?" she croaked.

There was no answer. Ignoring the pain in her head and neck, she turned to the driver's seat. It was empty.

* * *

FOUR YEARS LATER

Tegan woke in a cold sweat, breathing hard. The alarm on her phone was going off.

With a groan, she reached over and turned it off before dragging herself out of bed. She gave her shoulder an experimental roll and winced. She really needed to schedule another appointment with her physical therapist. Oh, the irony.

After showering and dressing, she shuffled off to the kitchen on autopilot. It took her three attempts to turn on the electric kettle before identifying the problem.

"I already turned it on."

She turned sheepishly to her best friend and roommate, Hannah Greer, who was sitting at the kitchen table with her mug. "Yeah, I... I realize that now," she mumbled.

"Shoulder bothering you again?" Hannah asked.

Tegan nodded. "Slept on it wrong. How'd you know?"

"Because your hair is still wet. You never bother with the hair dryer when your shoulder is bad."

She couldn't argue with that. She poured out the hot water into another mug and made herself some tea. As she slid into another chair at the table, Hannah's son Jamie came in, his shoes untied and his shirt on backwards. "Morning, Tea," he said, reaching for the cereal.

"Hey, kid," she said, smiling into her mug. "Is that a new fashion statement?"

"Huh?" She gestured at his shirt, and he laughed. "Yep, I definitely didn't do this on accident. All the kids in middle school are wearing their shirts like this."

"That's dope."

Jamie threaded his arms through the correct sleeves and twisted his shirt around. "Is your shoulder bad today?"

Tegan sighed and stood up. "I'm going to go dry my hair," she said flatly.

By the time she managed to tame her hair into submission, Hannah was herding Jamie out the door to drop him off at school before going to work. "See you later, Tea-Cake," she called. "Don't make anything for dinner, I'm getting takeout from the Thai place. I've been craving coconut shrimp."

"That sounds amazing. Have a good day."

As if on cue, Tegan felt something bump into her leg. She looked down to find Scully, her cross-eyed ginger tabby, staring up at her expectantly. "Where the hell have you been?" she demanded. "You heard the word 'shrimp', didn't you?"

After feeding the beast, she left the apartment and descended the stairs to the first floor, the cat trailing behind her. Arriving at another door, she unlocked it and stepped through into the dark bookstore. She switched on the lights and crossed the vast space, feeling a calm wash over her as she took in the rows and rows of books, all arranged exactly as she'd placed them. She went to work, waking up the computer at the checkout desk and turning on the espresso machine. Finally she unlocked the front door and flipped the 'Closed' sign to 'Open'.

The day passed slowly, with only a handful of customers coming in, and fewer buying anything. During a lull, Tegan decided to unload the shipment she had received the night before and add the titles to the store's online inventory. As she worked, she listened to the music on her phone, connected to a wireless speaker.

She was about a third of the way through the shipment when the desk phone rang. She paused the music and picked it up. "Good afternoon, Rag and Bottle Books. How may I help you?"

"_Uh, hi,_" said a male voice. "_I don't suppose you have a copy of 'The Feynman Lectures on Physics', do you?_" He didn't sound hopeful.

Tegan scrunched up her face in thought. "Richard Feynman, right? It's a three-volume set?"

_"Yes!"_ the voice exclaimed, startling her. "_Oh, my God, exactly. Do you have it?_"

She was busy typing the name into the inventory search field on her computer. "It looks like I have one copy," she said. "But let me check to make sure it's physically here. Can you hold for a minute, please?"

"_Absolutely._"

"Thanks." She put down the phone and hurried over to the science section. Her eyes scanned the titles until she found what she was looking for. Drawing out the red hardcover set, she returned to her desk and took the phone off 'hold'. "Success," she said. "I found it."

"_That's great! Could you hold it for me?_"

"Of course, sir. What's your name?"

"_Bruce._"

She wrote 'Bruce' on a sticky note and affixed it to the book's cover. "All right, Bruce. I have it set aside here for you to pick up. We're open until five-thirty."

"_I'll drop by this afternoon. Thank you so much._"

"You're very welcome."

She hung up the phone, and looked over at her cat, who was watching her from her window perch. "Well, that was mildly diverting," she told her. "Now back to our regularly scheduled tedium."

* * *

"So in our last class, we talked about the law of conservation of energy. Anyone remember what that states?"

A few hands shot upward in the crowded lecture hall of the Harvard Science Center. From his place at the lectern, Bruce Banner picked one at random. "Yes, go ahead."

"That the total energy of an isolated system is always the same."

"Exactly," he said. "Pretty simple, right? In other words, energy cannot be created or destroyed. Only transformed. Now what does that mean in practical terms? Well, let's say I have a ball, and I throw it up in the air." He picked up a baseball from the podium. "I'm going to try to throw it gently, because I don't want to get in trouble."

The class watched as Bruce tossed the baseball in the air and caught it a few times. "While the ball is moving, it has kinetic energy, energy of motion. As it goes up, gravity causes it to decelerate. It goes down, it accelerates. However, in that fraction of a second when it's stationary, and it's going neither up nor down, the ball has no kinetic energy. Right? Now you're thinking, 'Hey, Banner. You just said energy can't be created or destroyed.' So what happened? Where did all that energy go? Well, for one thing, the ball encountered wind resistance on the way up, so as it collided with the particles in the air, it caused heat in the form of friction. So it transferred some of its energy to the particles around it. It also transformed into potential energy, which is the energy stored in an object. As its kinetic energy decreases, its gravitational potential energy increases." He set the ball down.

"Let's look at another example," he went on, leaving the stage and moving into the audience. He stopped beside one of the students in the front row. "Let's say I pick up Mr. Cartwright here. Do you mind?"

With a nervous smile, the student shook his head and started to rise from his desk.

"No, no, don't get up." In a smooth motion, Bruce picked the young man up, desk and all, and held him over his head. The lecture hall erupted in laughter and exclamations of surprise.

"When I pick him up, I'm using the chemical energy, the ATP molecules in my muscles, to lift him," he said, still holding the man in the air. "But once he's up there, what happens to the energy? Some of it's being stored in gravitational potential energy, right? If I dropped him, it would turn back into kinetic energy. I'm not going to drop you," he assured him, earning more laughter from the audience.

"What else? My muscles generated heat, so that's thermal energy. Even moving him and the desk through the air generated heat. So none of this energy is coming out of nowhere, and none of it is going anywhere. It's just being transferred and transformed." Bruce returned the student to the ground. "Thank you, you're a good sport."

He walked back onto the stage. "Now, let's talk about internal energy. Internal energy encompasses all of the energy contained within the particles that make up a system, including potential and kinetic. This is represented, don't ask me why, by the letter U. So how do we measure a change in internal energy? Let's say we have a container filled with an ideal gas, like helium. If its internal energy changes, it's either doing something to change it, or something is being done to it. So here's how we write that."

Moving over to the whiteboard, Bruce picked up a marker in his large, olive green hand and began to write. "The change, which is expressed by the Greek symbol for 'delta'... What the hell is that? That looks like a gumdrop. Stupid giant fingers. Let me do that again." More laughter. "So change in the internal energy, or U, is equal to heat... which for some reason is expressed by the letter Q. Bunch of crackheads came up with these symbols. Change in energy is equal to heat added to the system, minus the work done by the system. Or plus the work done to the system."

He glanced up at the clock on the wall. "And there are other ways to express this, but we're out of time. So we'll get more into that next week. Have a great weekend. Use up some of that potential energy."

The students stood up and filed out of the lecture hall, saying their goodbyes as they left.

"Bye, Professor Banner."

"See you Monday, Professor."

"Good class today, Professor Hulk."

"Very funny," he said wryly.

Shaking his head, he erased his work on the whiteboard and placed his lecture notes in his messenger bag. As he did so, he saw another note he had written to himself earlier in the day: _'Pick up book_'. Cursing under his breath, he pulled out his tablet, which was connected to his phone's hotspot, and looked up the address of the bookstore. It was on Newbury Street, on the other side of the Charles River, just west of Trinity Church.

It was a little past four o'clock now. For a normal person, it was about an hour's walk.

He had plenty of time.

It was a lovely afternoon in late September, and as Bruce stepped outside onto Cambridge Street, he was met by the sight of students milling about Harvard Yard, enjoying the sunshine. He spotted a fellow professor with whom he had a passing acquaintance and waved at him, and received a tentative nod in return. He found that there were more than a few faculty members who still seemed intimidated by him, and he couldn't exactly fault them for it, given his history. He was, however, somewhat of a favorite among the students.

He cut across the Yard and made his way onto Massachusetts Avenue, heading east toward the river. On the way, he passed numerous abandoned buildings, their facades covered in ivy. It was still odd to see what was once a bustling city slowly being reclaimed by nature. It was a chilling reminder of how precarious humankind's position in the universe really was.

He passed over Harvard Bridge and found himself in the neighborhood of Back Bay. Here he was stopped several times by people requesting selfies with him. Bruce was happy to oblige them, but there was a part of him that still felt a sense of shock and disbelief that this was a regular part of his life now. If someone had told him ten years ago that he would be famous for something other than causing billions of dollars in property damage, he would have laughed in their face. Or, more likely, punched it.

Finally he arrived at his destination: a three-story brick building that appeared at one time to have been a warehouse. The sign over the double doors announced the establishment:

**Rag and Bottle Books**  
**est. 1989**  
**Rare editions and prints**

There was a flyer on one of the doors. Bruce fished his glasses out of his pocket and put them on, and the blurry letters resolved themselves. The flyer read:

_Hey nerds! Join our book club!_  
_Thursday nights from 6pm to 7:30_  
_Refreshments provided_  
_"There is no surer foundation for a beautiful friendship than a mutual taste in literature." — P.G. Wodehouse_

Bruce smiled. Pushing the door open, he ducked inside and looked around. He was pleasantly surprised. The shop was large and airy, but the space was exceptionally well-utilized. The tall shelves were crammed with books, arranged fastidiously according to author and subject. There seemed to be a section for every subject imaginable: philosophy, ornithology, green living, auto repair, arts and crafts. There were also displays meant to draw interest: 'Armchair mysteries', 'Time travel for young readers', 'I can't remember the title, but the cover was yellow'. He snorted as he spotted a collection of books on cocktail mixology with an accompanying sign that read, 'How to deal with your in-laws'.

There was no one at the cash register, so he decided to wander around. Presently, he was greeted by an orange cat with a serious case of strabismus. It seemed to be looking at him and at its own nose at the same time.

Bruce bent down to pet it, and it responded by leaping onto his arm and climbing up his sleeve to rest on his shoulder. "Ahh, Jesus!" he exclaimed in surprise. "Make yourself at home."

Accompanied by his new hitchhiker, he continued toward the back of the shop. As he did so, he could hear someone humming softly. He rounded another shelf, and found a woman standing next to a book cart, an earbud in one of her ears. She appeared to be in her early to mid-thirties, with light brown, freckled skin and honey-colored hair, which was pulled back in a messy ponytail. She was sorting books and putting them away. And she was singing Hall & Oates.

"High and dryyy, out of the rain," she sang, oblivious to Bruce's presence as she peered at the spine of a book before placing it on the shelf. "It's so easy to hurt others when you can't feel pain..."

Bruce watched her in amusement, trying to decide how to attract her attention without startling her. Fortunately, or perhaps unfortunately, he didn't have to wait long.

"You're a rich girl, and you've gone too far, 'cause you know it don't matter any— Whoa, _shit!_"

The book she was holding flew out of her hands into the air as her gaze abruptly landed on him. Reacting to the sudden outburst, the cat leaped off of his shoulder, causing him to stumble backward, bumping into the shelf behind him. He stood frozen in horror as it toppled over, crashing into the one beside it, until the rest fell like a row of dominos, scattering books everywhere.

Kinetic energy at its finest.

* * *

**Author's Note:** If you need help picturing Tegan, I've modeled her appearance after Rashida Jones. Because she's great. Plus she's admitted in interviews that she has a huge crush on Mark Ruffalo. So it seemed appropriate.


	2. Two: Superposition

**Author's Note:** Thanks for the follows and favorites, readers! Here's the next chapter.

* * *

**The Formula for Change**

Two: Superposition

For a moment, Tegan was powerless to do anything other than watch in a kind of paralyzed fascination as the bookcases overbalanced and tipped over: first one, then two, then half a dozen, coming to a stop only when the final bookcase collided against the far wall of the shop. Her books — her beautiful, perfect, meticulously arranged books — fell from their shelves at once, as if possessed of a sudden, single-minded urge to leap to their deaths. They tumbled and slid over each other in a cascade of fluttering pages until at last coming to rest in crazed heaps on the floor.

Slowly, she looked up at the perpetrator of this act of wanton destruction and blatant disrespect for literature. The huge green man was also frozen in place, covering his face with a massive hand. Tegan's initial reaction upon seeing the infamous Hulk in her bookstore had been one of pure terror, but after the temporary distraction of watching her place of business literally come crashing down around her, she now realized that her visitor had not actually done anything violent. On the contrary, he appeared to be utterly mortified.

She exhaled slowly, trying to calm her racing heart. Now that she was in a more rational state of mind, she allowed herself to examine the man more closely. There was no doubt that this was the Hulk, but it was not the Hulk she knew from pictures and video footage she'd seen in the past. There were three reasons to support this assessment. First, he was not quite as enormous. Second, he was not smashing things (at least, not on purpose). And third, he was wearing clothes.

Dark jeans and a sport coat, to be precise, with... Were those elbow patches?

And glasses. Wait. The Hulk needed glasses?

What the hell?

With a start, she realized he was talking to her. In complete, grammatically correct sentences.

"I am so, so sorry, ma'am," he was saying, as he began picking up books in a somewhat futile attempt to restore order to chaos. "I didn't mean to startle you, although in hindsight I probably should have seen it coming. I will clean all this up, I swear."

As she listened to his voice, Tegan was struck by its familiarity. It was deeper than she remembered, but still unmistakable. He was undoubtedly the Hulk, but somehow, at the same time, he was also...

"Dr. Banner?" she asked uncertainly.

"Yeah, that's me," he replied, abashed. "Needless to say, first impressions are not my strong suit." With a sigh, he placed the books he'd collected on the nearby cart. Then, as he turned to face her, he seemed to look at her for the first time.

"Wait a second," he said, his dark eyebrows knitting together. "Ms. Thomas?"

* * *

SIX YEARS AGO

Tegan stood in the gleaming elevator as it rose toward the penthouse of Avengers Tower, watching the numbers climb and wringing her hands nervously. After inquiring at the front desk in the building's massive, opulent lobby, she had been escorted to a private elevator, told that Mr. Stark was expecting her, and that she was invited to go right up. Never in her life had she heard anything so ridiculous. Except perhaps the phone call she had received the day before.

As a fairly renowned physical therapist and personal trainer based in New York, Tegan had had several high-profile clients in the past, including celebrities, politicians, and professional athletes. She was no longer prone to getting starstruck by a famous face. All the same, when she had been told that Tony Stark — billionaire, humanitarian, mad scientist inventor, and, of course, Avenger — wanted to hire her on retainer as his physical therapist, she had not known quite how to respond.

It made sense, she supposed. He was Iron Man. That was not an easy job. And even with his highly sophisticated mechanical suit of armor, he was only human. It was to be expected that he would sustain injuries that would require care. No doubt he or one of his staff had learned of Tegan's practice and had been favorably impressed. Her reputation spoke for itself.

Then again, so did his.

The man was notoriously stubborn and uncooperative, both with government officials and international agencies. In interviews, he seemed to treat everything as a joke or an opportunity to show off. In short, he seemed like a total jackass.

Did she really _want_ to take on Tony Stark as a client?

In the end, of course, she had agreed to meet him at Avengers Tower. At the very least, there was a chance that she might catch a glimpse of Captain America while she was there. He was like... a perfect human man.

The elevator slowed to a halt, and the doors slid open to reveal a large, open lounge area with several low couches and a bar. As Tegan stepped out, she was greeted by a tall, slender woman, impeccably dressed, with long strawberry blonde hair. Virginia "Pepper" Potts.

"Ms. Thomas," she said, extending her hand. "Thank you for coming. I'm Pepper."

_Yes, I know,_ Tegan almost said before restraining herself. "Pleased to meet you," she answered, shaking her hand and feeling hideously under-dressed in her slacks and teal blazer. They suddenly seemed snug in all the wrong places.

"Tony is in his lab, but he'll be up here shortly," Ms. Potts said, inviting her to take a seat on one of the sofas. "Can I get you anything while you wait? Water, coffee, Earl Grey latté?"

Tegan shook her head automatically. "No, thank you, I—" She stopped, frowned. "How did you know I..."

The woman chuckled. "We do our research around here."

The elevator door opened again, and a voice rang out behind her: "Oh, good, you're here."

Tegan rose to her feet without conscious thought as Anthony Stark strode briskly forward and shook her hand. He was shorter than she had expected, and was dressed casually in jeans and a Rolling Stones shirt. "Hi," he said without ceremony. "Haven't been waiting too long, I hope?"

"Not at all," she managed to reply.

"Great. I want you to meet someone."

For the first time, Tegan noticed another man behind Stark and off to one side. He was roughly the same height and age, with dark, curly hair, spectacles, and a somewhat frazzled air. He was standing hunched over, with his arms folded over his chest, as if unintentionally trying to make himself disappear.

"This is Dr. Bruce Banner," said Stark. "Bruce, this is Tegan Thomas. Both your names are alliterative, isn't that fun?"

The man uncrossed his arms and came closer, taking her hand. "Nice to meet you," he said quietly.

Tegan smiled, doing her best not to stare. "Hello."

_Bruce Banner._ The man who, through some manner of transformation which should not have been possible, occasionally turned into the giant, green, unstoppable being of pure rage known as the Hulk.

Dimly, she was aware of Ms. Potts politely excusing herself and leaving the room. "Ms. Thomas here is a physical therapist and personal trainer," Stark was saying to Banner. "She has quite the impressive portfolio. I'm hoping to hire her on retainer. I've got that knee thing, you know. Keeps popping and locking. Pretty sure it's not supposed to do that."

"Which knee has been causing you discomfort?" Tegan asked, trying to focus.

"Obviously, it goes without saying," Stark continued, ignoring her question, "that your skills would be called upon frequently, and not solely by me. The others are every bit as accident-prone and terrible at self-care as I am. Would you be up to the task?"

Tegan's mouth fell open, and she quickly closed it. "The others," she repeated. "As in, the other Avengers."

"Yeah," he said, as if it were the most obvious thing in the world. "Are you cool with that?"

For a moment all she could do was stare at him.

"Absolutely," she heard herself say.

Stark clapped his hands, startling her. "Excellent. You can start with Banner here."

Banner suddenly looked considerably more alert. "Uhhh, what?"

"Part of Ms. Thomas's credentials include a license in massage therapy," Stark told him off-hand, before turning back to Tegan. "I know this is short notice, but I would consider it an inestimable boon if you could carve an hour out of your busy schedule to give my friend Bruce here a massage. What do you say?"

Banner was shaking his head vehemently. "I don't, uhh... That's okay. You don't have to... I'm— I'm fine, really."

Stark gave him a pointed look. "Are you finished babbling?"

The other scientist glared silently at him.

With a sigh, Stark addressed Tegan again. "As you can see, the man is a rubber band waiting to snap, and if he does, he's one hundred percent going to kill all of us." He smiled as he spoke, but his tone was very serious. "If it'll help, you can think of this as a working interview."

_More like a litmus test,_ she thought, returning his steady gaze. "Of course," she said. "I'll need a massage table and a quiet space to work in."

"Down that hall, third door on the left."

"In that case, please follow me, Dr. Banner."

The man looked back and forth between Tegan and Stark, visibly upset at being put on the spot, but not wishing to be rude. With a final baleful glance at the billionaire, he reluctantly followed Tegan out of the lounge.

The room had clearly been waiting for them. A massage table had been set up, a stack of sheets laid on top of it. The lights were dimmed, and soft music was playing from some unseen speakers. Her entire interview had been an ambush.

Tegan's fists clenched at her sides until her fingernails bit into her palms. Beside her, Banner seemed to shrink even further into himself. "I should have seen this coming," he said in a low voice, not looking at her. "Tony's been bugging me to get a massage for months now. I'm sorry he got you involved, Ms. Thomas."

"Don't be," she told him firmly. "None of this is your fault. This whole thing is a dick move, and I have no intention of going along with it."

He looked at her in surprise, brown eyes wide behind his glasses. "You're not?"

She motioned him into the room and shut the door behind them. "No, I'm not. Tony Stark may be accustomed to having his every whim indulged, but this isn't about him. This is about you, Dr. Banner. Whether or not you might benefit from massage therapy, or any other kind of therapy, is irrelevant. I don't treat patients against their will."

Banner swallowed. "I appreciate that."

Tegan sighed and leaned back against the door. What a total waste of time.

"So," Banner said after a short silence. "What happens now?"

She shook her head. "I don't know. Nothing. I figure we wait here for a while, then you can tell him... whatever you need to tell him to get him off your back. And I can politely decline his offer of employment."

He frowned at this. "I don't want you to turn down a job because of me," he protested.

"It's not because of you," she assured him. "And I don't need the job."

Banner didn't look convinced, but he didn't debate the issue further. He began to pace the room restlessly, his hands in his pockets. Tegan watched him, interested despite the situation they had found themselves in. He was handsome, but not intimidatingly so, like his fellow Avengers, Steve Rogers and Thor. He definitely did not look like a fighter. Everything about him, from his posture, to his far-sightedness, to his rumpled clothes which seemed to have been picked at random, marked him unmistakably as a scientist.

He really didn't belong here.

And his pacing was driving her crazy.

"You don't relax often, do you, Doctor?" she asked before she could stop herself.

Banner's smile was forced. "I don't really have the luxury," he said, ceasing his pacing with an effort.

"Why is that?"

His eyes took on a haunted quality as he considered her question. "I'm not... safe," he finally answered, his voice low and tired.

Tegan felt a pang of sympathy for the man. "Dr. Banner," she said quietly. "I can't tell you what to do. But I have to say that while Mr. Stark's methods in getting me here were manipulative and under-handed and... not cool at _all_... I do think he meant well. And I believe massage therapy might actually be beneficial in relieving some of your obvious tension."

The man gave a mirthless laugh that was more of an exhalation. "Obvious tension," he repeated. "That's... accurate."

She smiled at him. "It's entirely up to you," she said. "But I _am_ already here."

He arched a skeptical eyebrow at her. "Do you really think it could help me?"

"I do."

Banner sighed. Removing his glasses, he pinched the bridge of his nose between his fingers. "All right, what the hell," he finally said.

"You sure?" she asked. "I don't want you to be uncomfortable."

He smiled again, and for the first time, it reached his eyes. "It's fine. 'Uncomfortable' is my default setting."

Arranging the sheets on the massage table, Tegan told him to undress and lie face-down under the top sheet. Then she stepped out of the room and waited in the hall. After a sufficient amount of time had passed, she knocked lightly on the door, and was told she could enter. Stepping inside, she removed her blazer and draped it over a chair, along with Banner's clothes.

She looked around for some type of massage oil. Sure enough, she found a bottle on a nearby table. She poured some out and rubbed it into her hands, warming them up. Then she turned to Banner, who was lying stiffly on the table like a piece of petrified wood. "Where would you say you experience the most tension?" she asked.

He was silent for a beat. "I'd say my neck and shoulders," he replied, his voice muffled by the cushioned face cradle.

Tegan nodded. "Upper back?"

"Yeah."

She began to loosen up the muscles in his shoulders, unsurprised to find them full of knots. In response, he inhaled sharply through his teeth. She paused. "Too hard?"

"No, it's good."

She continued to break up the adhesions, trying to be as gentle as possible. Slowly, she worked her way down his back and legs, then moved to his arms. He had surprisingly good muscle tone, for a man who spent most of his time in a laboratory. She wondered if it was a side effect of the bizarre accident that had created his green counterpart. As she worked, she fell into a trance, as was her habit. She forgot where she was, who she was working on, and even how she'd gotten there in the first place. In truth, it was almost a kind of therapy for her, as well.

Gradually, Banner relaxed, and his breathing slowed. Tegan told him to turn over, holding the sheet in place while he did so. Then she began to massage his head and neck. His splenius capitis muscles, which connected the cervical spine to the back of the head, were unbelievably tight and in spasm. The amount of stress he had to be under on a constant basis was probably more than she or anyone else could comprehend.

She watched his face closely now. His eyes were shut, his lips slightly parted. He appeared ten years younger than he did when she had met him. The more she looked at him, the more difficult she found it not to look away. What kind of hell was his life like?

At length Tegan finished, and drew the sheet up to cover his body. "Rest here for as long as you need, and come out whenever you're ready," she told him in a whisper.

Banner mumbled something unintelligible, and she smiled. Grabbing her jacket, she retreated into the hall once again.

This time Tony Stark was waiting for her.

"How'd it go?" he asked. He was holding a couple of bottles of chilled water, and he offered her one.

She took it and walked past him, not saying anything.

"I get it," he said, following her into the lounge. "I should have told you why you were here. I should have told _Bruce_ why you were here. But now that you've met the guy, do you really think he would have agreed to it?"

Tegan stopped and turned to face him. "That's beside the point, Mr. Stark," she said evenly. "You blindsided both of us, and I don't appreciate it. We're all extremely fortunate that Dr. Banner is as gracious as he is. This could have gone very badly."

Stark shook his head. "I wouldn't have asked you to come if I thought you'd be in any danger, Ms. Thomas. Bruce has an exceptionally tight lid on his emotions and, frankly, a baffling amount of self-control. That's precisely why he needed this. The man has no outlet for his stress. He's a nuclear reactor with no safety relief valve. I can't..." He trailed off and shook his head. "He's my friend. I had to do something."

Tegan was surprised by the genuine concern in his voice. "I can understand that," she said, feeling some of her anger drain away. Then she narrowed her eyes at him. "So I take it you don't actually have any interest in hiring me as a physical therapist?"

"Oh, no, I do," Stark assured her. "And this is still very much a working interview. You're doing super, by the way."

He gave her a thumbs-up. Tegan resisted the sudden urge to squeeze her water bottle into his face.

Thankfully, at that moment, Banner walked into the room. His hair was a mess, and his shirt was misbuttoned.

"Hey, buddy," said Stark, handing him the other water bottle. "How do you feel?"

"First of all, I hate you," Banner replied, unscrewing the cap and taking a sip. "But I'm also feeling... very relaxed." He cast a grateful glance at Tegan. "It's a new experience for me."

Stark broke into a grin. "You hear that, Ms. Thomas? That settles it. You're hired."

"On one condition," said Tegan, returning Banner's gaze. "That you never pull any shit like that on me or your colleagues, ever again."

Banner smiled.

Stark blinked. "Done," he said. "Welcome aboard."

* * *

"Ms. Thomas?"

"What?" Tegan blurted, unthinkingly.

The large, green, Banner-Hulk person in her shop smiled broadly. "I knew it. Avengers Tower. You're the physical therapist. Tony tricked you into giving me a massage." He chuckled, shaking his head. "God, that was so long ago. Again, I am so sorry about this. It's good to see you, though. Your hair is different."

Somehow Tegan was able to find her voice. "You've, uhh... changed a bit, too."

He chuckled again. "Yeah, you could say that."

She wanted to slap herself to make sure she wasn't dreaming. This was all so surreal. "If I may ask... How?"

Banner gave a shrug of his massive shoulders. "Long story short, I stopped fighting the big guy, and he stopped fighting me," he replied. "It only took fifteen years for me to realize he wasn't a monster trapped inside me. He _was_ me. Once I accepted that, it was easier to... bring us together."

Tegan shook her head in mingled amazement and disbelief. "That's..." She trailed off as she made the sudden connection. "_Bruce_," she said, feeling like an idiot. "You're the one who called about the Feynman Lectures."

He nodded sheepishly and began standing the fallen bookcases upright again, seemingly with no effort at all. The books, of course, were still scattered all over the floor.

Tegan watched him in fascination, unable to take her eyes off of him. He talked like Bruce Banner, and he had the same mannerisms and facial expressions, including that peculiar quirk of his eyebrow. But there was no trace of the nervous energy or troubled soul she remembered from six years ago.

It reminded her of a YouTube video she'd watched one night on the subject of superposition. She had had insomnia and was looking for something boring enough to lull her to sleep, and instead had found herself fascinated. The general gist was that according to quantum physics, a particle could be two things simultaneously. A photon, for example, was a particle, but it was also a wave.

Somehow, this man was Bruce Banner and the Hulk at the same time.

"No offense," she told him, "but I would think a guy like you would already own the most famous book on physics in the English language."

As she spoke, her cat Scully, who had been regarding Banner warily since the incident, now approached cautiously and head-butted the man's leg. "I just moved here fairly recently," he explained, scooping up the cat and moving her gently to one side. "I'm still unpacking, and I realized some of my books seem to have gotten lost in the move."

"I feel your pain," said Tegan. She had lost quite a few books that way, too.

He finished restoring the shelves to their original positions. "So, you work here now," he said, gesturing vaguely at their surroundings. "You're not a physical therapist anymore?"

Tegan shook her head. "I was in a car accident. Broke my scapula, clavicle, and several ribs. I lost a lot of strength in my right arm. Physical therapy is demanding work, and I just couldn't do it anymore."

"I'm sorry," Banner said quietly. "When was this?"

She cleared her throat. "It was... when Thanos..."

He grew still. "Oh," he murmured.

Suddenly he looked much more like the Bruce Banner she remembered. She'd seen that look in his eyes before.

Eager to change the subject, Tegan motioned him to follow her to the front of the store, away from the disorder. "Anyway, what brings you to Boston?" she asked conversationally.

He roused himself from his reverie. "I'm teaching at Harvard," he answered.

Her eyebrows climbed upward. "Wow," she said, impressed. "What are you teaching?"

"Particle Physics, and Biological and Biomedical Sciences."

"Sounds like brain-meltingly good fun," Tegan remarked, making him chuckle. "I'm sure your students love being taught by the Hulk."

Banner smiled wryly. "Actually, they call me '_Professor_ Hulk'."

"That's fantastic," Tegan said with a laugh. "Oh, before I forget." She reached across the cashier's desk and retrieved the thick, three-volume set. "Here's your book."

"Thank you." He took out his wallet and handed his card to her. The plastic rectangle looked ridiculous in his enormous hand. "Will you let me help clean up this mess?"

Tegan waved a dismissive hand. "That's all right," she told him. "It won't take me that long to put it all back. I'll just close the shop for the weekend and—"

"Close your shop?" Banner sounded horrified, as if she had just proposed stuffing her cat in a burlap bag and hurling it into the Charles River. "But you'll lose business."

She smiled at his concern. "It's fine, Doctor," she assured him, returning his card. "I don't actually need the money. This place is more of a hobby than anything else."

"Please," Banner insisted. "I feel terrible."

Tegan looked up at him, straining her neck slightly to do so. His brown eyes pleaded with her silently behind his glasses. Combined with his huge stature and incongruous, scholarly attire, the whole effect was comically pathetic.

Hiding a smile, she walked past him to the front door and flipped the 'Open' sign over to 'Closed'. Then she turned back to him.

"First I'm going to make some tea," she said. "You want some?"

* * *

**Author's Note:** Quantum superposition is actually way more complicated than the way I described it. But hey, I'm no Brian Cox. Or am I? No, I'm not.


	3. Three: Spontaneous Human Combustion

**Author's Note:** Thanks again to all who faved and followed. Sorry for the delay in updating.

* * *

**The Formula for Change**

Three: Spontaneous Human Combustion

Bruce bent down and picked up a book from the pile at his feet. The cover depicted a balsa-wood raft sailing over the surface of an azure ocean. "_Kon-Tiki_, by Thor Heyerdahl," he read aloud.

"That would be under 'Travel Literature - Maritime'," replied Tegan Thomas, taking the book from his hand and placing it on a nearby labeled shelf. "Ever read it?"

"I've seen the movie," he said. "Does that count?"

Ms. Thomas's lips twitched, as if she were trying not to smile. "Absolutely not."

Bruce chuckled. "I'll add it to my Goodreads list."

He glanced over at the woman as she continued returning books to their proper places. It was very strange, seeing her again. He had only met her once, shortly before the incident with Ultron. She had made a favorable impression on him that day at Avengers Tower. She had seemed intelligent, self-assured, and compassionate, and he had admired the no-nonsense way she had dealt with Tony. She gave a hell of a massage, too.

And then he had been pulled into the Battle of Sokovia, transformed into the Hulk, and spent two years on an alien planet. When he had finally returned to Earth, the immediate threat of Thanos had eclipsed everything else. In truth, he had completely forgotten about Tegan Thomas.

He watched as she paused in her work to take a sip of tea. (He had knocked back his own in one swallow, which had afforded her considerable amusement.) She looked much the same as the last and only time he had seen her, except the fact that she was six years older. Her hair, as he'd needlessly pointed out, was different; where before it had been short and dark, it was now longer, and more of a lighter, caramel shade of brown. It suited her.

"Speaking of guys named Thor," she said, setting her mug of tea aside, "do you know what he's up to these days?"

Bruce nodded. "He's in Norway, with what's left of the Asgardians," he answered. "Last I heard, he was doing all right." He cleared his throat. "I haven't talked to him in a while."

He felt a stab of guilt as he spoke. He really hadn't made much of an effort to stay in touch with his fellow Avengers, save for an occasional text or email. Tony, Steve, and Natasha were in New York, Rocket, Nebula, and Carol were off-world, Rhodey was all over the place, and Clint... Clint had lost his mind. Or maybe his soul.

Bruce still communicated with Tony fairly regularly, but as for the others... He really didn't have much in common with them beyond their former shared mission to defend the Earth, which had blown up in their faces. The truth was, he had always felt like an outsider, even within their group. Bruce Banner had never been an Avenger, a member of the team. He was an asset. The Hulk had been the one they had called on when they needed help.

And in the end, they had both failed.

The shop's resident cat bumped his leg, bringing him out of his melancholy thoughts. At the same moment, Ms. Thomas spoke again:

"What about the others?"

He suppressed a sigh. "Hanging in there," he said, absently scratching the orange feline under its chin. "For the most part." He didn't know how well she had known Clint, but he didn't want to be the one to tell her he had become an internationally wanted assassin. He had done a pretty good job of ruining her day already.

The thought that she had known the others brought a question of his own to mind. "How long did you work for Tony?"

"A little over a year. Until the Avengers split up. The first time," she clarified. "When half of them became fugitives, I decided to move on. I stayed to help Colonel Rhodes after his accident, just until he got the hang of his leg braces. But I figured it was probably time to find safer work."

Bruce couldn't blame her. "And how did you end up working here?" he asked, handing her another book.

She gazed thoughtfully down at the cover. "This was my dad's bookstore," she said. "He opened it in the eighties. But after the, uhh... Decimation? Is that what they're calling it?" She gave a snort. "Seems inaccurate, since it technically means reducing something by ten percent, and half the population was wiped out."

She fell silent, still staring down at the book. With a visible effort, she collected herself. "Anyway, my dad passed away, along with my mom and my brother, so everything was left to me."

Bruce felt a heavy, sick sensation settle in his stomach, like he'd swallowed a boulder. "God, that's... I'm so sorry," he said softly.

There was another, longer silence. Then she spoke in a low voice. "You know, for a long time, I blamed you. Not _you_ specifically," she added hastily. "But I did blame the Avengers. I thought, I don't know, you must not have tried hard enough, or something." She sighed. "But that wasn't fair of me. I mean... if even 'Earth's Mightiest Heroes' couldn't stop Thanos... what chance did we ever really have?"

He knew what she meant. He had asked himself the same question a thousand times. Could they have done more? Or had they always been doomed to fail? He would never know.

With a decisive motion, Ms. Thomas slid the book into place on its shelf. "You did everything you could," she said. "I can't be mad at you for that."

Bruce was unexpectedly moved. "That means a lot to me," he said quietly.

She glanced down at her watch. "It's getting late. Why don't you go on home? I can get the rest of this tomorrow."

He looked around. They had made some progress in cleaning up the mess, but there was still a lot more work to be done. "What time should I be here?" he asked.

Ms. Thomas gave him a look that was a mixture of gratitude and exasperation. "Dr. Banner—"

"Bruce," he insisted.

Slowly, reluctantly, she gave in to a smile. "How about nine o'clock?" she suggested.

Bruce nodded in agreement, and they walked to the front of the shop, tiptoeing around the scattered books. "Don't forget your _Feynman Lectures_," she reminded him.

"Oh, yeah. Thanks." He picked up the volumes from the front desk and tucked them into his messenger bag. He turned to leave, then hesitated. "Listen, I don't want to sound creepy, but do you live nearby? Because if you have to walk home tonight, I feel like I should probably go with you, just to be safe."

She shook her head. "Not necessary," she replied, still smiling. "I live upstairs. But if I ever need a bodyguard, you'll be the first person I call."

Bruce chuckled sheepishly. "Right."

She held out her small brown hand. He took it gingerly in his own massive one, enveloping it completely. "Good night, Ms. Thomas."

"Tegan."

He smiled. "Tegan."

Releasing her hand, he turned and left the shop. Outside, the sun had set, and the streets were dark and empty. As he stood on the sidewalk, the lights inside the bookstore went out one by one. Then, with another smile, he made his way home.

* * *

After locking the doors and turning off all the lights, Tegan left the bookshop, carrying the cat under her arm like a football. She entered the stairwell and climbed the flight of steps to the second floor. Outside the door to her apartment, she gave a perfunctory knock before entering.

"Hey," she called to Hannah and Jamie, who were seated at the dining table, which was littered with takeout containers of Thai food. "Sorry I'm late."

"Took you long enough," Hannah said, her mouth full of green curry. "I was just about to send Jamie down to collect you. We've eaten almost all the coconut shrimp."

"Truly shocking," Tegan dead-panned, putting down the cat and making a beeline for the dish cupboard. "That's okay. I was detained. Some of the bookcases got knocked over. I was cleaning them up."

"Why didn't you come up and get us?" Hannah asked. "We could have helped you."

She gave a nonchalant shrug as she grabbed a plate and sat down at the table. "I had help."

Her friend frowned in disbelief. "Who helped you?"

Tegan suppressed a smile. "Bruce Banner," she said casually.

Hannah snorted, blowing her curly red hair out of her face. "Shut up."

With another shrug, Tegan proceeded to pile _pad khee mao_ onto her plate. When she gave no answer, Hannah narrowed her eyes at her. "Wait, you're serious?"

Tegan nodded. "He's the one who knocked the bookcases over in the first place."

Jamie dropped his chopsticks with a clatter. "Hold up," he said. "The guy who turns into the Hulk was _downstairs_, and you didn't tell me?"

"He's coming back in the morning to finish helping me with the books," Tegan told him. "If you promise not to act like complete lunatics, you both can meet him." She paused as she took a bite of noodles and swallowed. "I feel I should probably warn you in advance, though. He's, um... different now."

"Different now?" Hannah repeated. "Different _how?_"

"Well," she said slowly, "he can't really turn into the Hulk anymore... because he already _is_ the Hulk."

"What the hell are you talking about?" Hannah demanded.

Tegan threw up her hands with a helpless gesture. "I can't explain it. He somehow managed to merge Banner and the Hulk into one person. I don't know how he did it. I suspect I wouldn't understand it even if he explained it to me."

"What is he doing in Boston?" Jamie asked curiously.

"Teaching. At Harvard. Because that's totally normal." Just talking about it brought the surreality of the whole evening back to her. It had been surprising, how quickly she had grown accustomed to the sight of Bruce Banner's towering green presence as he handed her books, drinking tea, playing with her cat, and chatting away as if they were old friends. After a while, it had ceased to be unusual. In fact, it had been... rather nice.

"I never thought I'd see him again," she mused aloud. "I only met him the one time, right before the whole Ultron fiasco. He vanished after that. Then two years later, there he was on TV again, at that press conference, answering questions about the Decimation alongside the other Avengers. He said he'd... been on another planet?" She shook her head. "That's probably not even the weirdest thing that's ever happened to him."

Hannah wiped her lips with a napkin. "That guy has serious issues," she said emphatically.

Tegan's brow furrowed in thought. "I don't know," she replied. "It seems like he's worked most of them out. He's not at all like the neurotic, anxiety-plagued Bruce Banner I met six years ago. He's... actually... not hating life anymore."

Her friend made a skeptical noise. "I hope you're right," she said, unconvinced. "I don't want to have to find another place to live if he tears this one apart."

"Scully likes him," Tegan pointed out, glancing down at the cat, who was waiting at her feet for something to drop.

"Scully's an idiot."

Tegan blinked. "That's... fair."

"Can I really meet him?" Jamie asked her.

She smiled. "Sure, kid," she assured him. Then she laughed as he picked up his last, precious shrimp and bestowed it on her plate.

Later that night, after washing her face, brushing her teeth, and changing into an old tank top and frayed pajama bottoms, she crawled into bed with a book. Immediately the cat hopped up onto the mattress and curled up on her stomach. For some reason, Scully had never learned that cats were supposed to be nocturnal. Tegan supposed Hannah was right; she was a bit of an idiot. But as long as she didn't tear through the apartment like a maniac all night, she wasn't about to complain.

She scratched the cat under her chin, remembering how Banner had done the same earlier with his ludicrously oversized fingers. Scully hadn't seemed to mind.

"You liked Dr. Banner, didn't you?" she asked the cat. "Sorry. _Bruce_."

Scully began to purr.

"I concur."

The next morning, promptly at nine o'clock, Tegan went down to the bookstore, leaving the cat upstairs where she couldn't inadvertently cause another disaster. She found Banner waiting outside the front door. He was dressed in jeans and a grey henley shirt, which made her wonder where exactly he found clothing to fit his frame. He was also holding a stack of boxes in one hand, and as she came forward to unlock the door, he waved through the glass with the other.

"Well, good morning, Punctual Avenger," she said with a smile as she stepped aside to let him in. "What's in the boxes?"

"Doughnuts," was his reply as he set them down on the checkout counter. "Four dozen of them, to be precise."

"I hope you're not expecting me to eat all of them," she joked.

"I am not. Unfortunately, it takes a lot to keep this ridiculous body functioning. My caloric consumption can only be described as 'obscene'." As he spoke, he rubbed his stubbled chin. "And I am now realizing that I'm a jackass, because I didn't consider the possibility that you might have food allergies."

She shook her head. "It's all good. And that's very sweet of you."

Banner - or rather, _Bruce_, she reminded herself - gave a shrug. "It's the least I could do. Literally. Because I didn't make them." He cleared his throat awkwardly. "Sorry, I don't talk to a lot of people in a non-academic setting."

"You're doing fine," Tegan assured him. "By the way, I was wondering if I could ask a small favor of you. One of my roommates is dying to meet you. I hope you don't mind if he comes down for a bit."

"Not at all," he said.

"I appreciate it." She took out her phone and sent off a quick text to Jamie before putting it away. "It's my best friend's son. He's twelve, and he was most displeased to learn that the Hulk was downstairs last night and nobody bothered to inform him."

He gave a self-deprecating chuckle. "And to think there used to be a time when children would scream and weep at the sight of me. Now they beg me to toss them in the air."

"Do you?" Tegan asked, alarmed.

Bruce looked at her with a guarded expression for several seconds. "Not... _really_ high."

Before she could question him further, the back door flew open and Jamie all but exploded into the room. Carefully, he picked his way around the books still scattered all over the floor and came forward. As he looked up and his gaze fell on Bruce's massive figure, he stopped in his tracks, his eyes wide and his mouth hanging slightly agape. He vaguely resembled, Tegan thought, a landed trout.

"This is my favorite guy in the universe," she told Bruce, "Jamie Greer. Jamie, this is Dr. Banner."

"Hey, Jamie," said Bruce, extending his hand. "How's it going?"

Jamie stared openly at his massive hand before placing it slowly in his. "Good," he replied, sounding a bit dazed.

"What grade are you in this year, Jamie?" he asked, releasing the boy's hand.

Jamie continued to stare up at him, until Tegan nudged him with her elbow. "Seventh," he blurted.

"Seventh," Bruce repeated, nodding. "What's your favorite subject?"

"Uhh... Chemistry."

The man arched an eyebrow. "Excellent choice," he said, impressed. "Science for the win, pal."

He held out his closed fist, and Jamie bumped it with his own, a shy smile stealing over his face.

"Dr. Banner is teaching science classes at Harvard," Tegan informed Jamie. "Particle physics, and..." To her embarrassment, she couldn't remember the other subject. "Oh, crap."

Bruce smiled wryly. "That's right," he said with a teasing glance at her. "Study hard, and when you're old enough, you can sign up for my classes and learn some physics and crap, too."

"I will," said Jamie, laughing.

Rolling her eyes, Tegan reached up and tousled the boy's curly red hair. "We're reshelving books. Want to help?"

"Do I have to?"

"If you want doughnuts, you do."

Jamie pretended to deliberate on this. "Yeah, okay."

Together, they set to the task of restoring order to the bookstore. This time the work went much quicker; being better acquainted with the shelves, Bruce took less time to determine where each book belonged, and only occasionally needed to consult Tegan. Jamie was assigned the job of picking up and sorting all of the children and young adult books.

"Hey, Aunt Tea," he said, holding up a dog-eared paperback. "Remember this book? You read it to me when I was a kid."

"You still _are_ a kid, kid," she told him, squinting to make out the title. "_Island of the Blue Dolphins_. I did read that to you, didn't I? I'd almost forgotten."

"You have good taste," said Bruce with a faint smile. "My mom read that to me, too."

Tegan glanced over at him, crouched among the stacks of books he had separated by subject. His thick dark eyebrows were knitted together, and behind his glasses, his eyes held a sudden, deep sadness. Quickly, she looked away, feeling as if she were intruding on some painful private memory. She knew all about those.

"I think Tea only read it to me because it had the word 'dolphins' in the title," Jamie was saying. "She's obsessed with them."

"I read it to you because it's a beautiful tale of survival and the resilience of the human spirit," she said dryly.

"Then how come when you were finished, you said, 'Three out of five stars, not enough dolphins'?"

"That was a joke. How do you even remember that?"

The back door opened, and they looked up to see Hannah tiptoeing hesitantly into the bookshop, as if afraid of startling Tegan's famously volatile guest. "Hey, sorry to interrupt," she said in a comically hushed voice. "I'm Hannah, Jamie's mom."

Bruce appeared amused as he rose to his feet and shook her hand. "Bruce. Pleased to meet you. Don't worry, I don't smash anymore. Except when I'm trying to assemble IKEA furniture."

"Understandable," said Hannah, laughing. She turned to her son. "Jamie, did you forget you're supposed to go to Matteo's today to work on your History project?"

"No, but I was hoping you had."

Hannah snorted. "Nice try. Get upstairs and get ready. And pick up all those dirty clothes in your room. It looks like a laundromat exploded in there."

"Oh, my God, Mom, not in front of the Hulk," Jamie mumbled under his breath, causing Bruce to turn away to hide his smile. "Later, Aunt Tea. It was nice to meet you, Dr. Banner."

"You, too, Jamie."

The boy grabbed another doughnut before following his mother upstairs. "Cute kid," said Bruce after they'd gone. "So he and his parents live here with you?"

Tegan shook her head. "Just him and his mom. His dad didn't survive the Decimation. He was my cousin, actually, which makes us all kind of related." Not for the first time, she wondered how she had ended up losing so many loved ones. The number seemed disproportionately high to her.

She cleared her throat. "Anyway, Hannah and I have been best friends since we were about Jamie's age. When Thanos... happened... I invited her and Jamie to move in with me. I had the space, and the thought of living alone was not one that appealed to me."

"Were you married, too?" Bruce asked quietly.

The question caught her off guard, even though it shouldn't have. She swallowed hard. "Engaged," she said tightly. "He didn't survive the Snap, either."

Bruce sighed softly. "I'm sorry," he murmured.

Tegan barely heard him, caught up in memories of her own. Memories of arguments that never went anywhere, of stories that sounded too outlandish to be true, of feeling as if she couldn't trust her own judgment. Of living in a constant state of fear and not even knowing why.

After an awkward moment of silence, Bruce bent down and picked up another book - a paperback with an array of tropical fish on the cover. "'Marine Biology'?" he suggested.

Tegan smiled at his rather transparent attempt to change the subject. "Close. 'Aquarium Care - Handbooks and Guides'."

He clucked his tongue. "Swing and a miss," he said, making her chuckle.

They continued working, falling into a sort of groove. At length, all the shelves were filled, leaving only the overstock books which were kept on the very highest shelves. Bruce did not even have to stretch to replace them.

"I have a question for you," he said at one point.

Tegan passed him another handful of books. "Oh?"

He arranged the books in a neat stack on the highest shelf. "'Rag and Bottle Books'. Where does that name come from? What's the significance?"

"My dad was a huge Dickens nerd," she said. "_Bleak House_ was his favorite. There's a character in it named Krook, who owns a shop which is more or less a catch-all for every kind of junk imaginable: books, bottles, paper, clothes, kitchenware. 'Everything seemed to be bought and nothing to be sold there.' And it was called 'Krook's Rag and Bottle Warehouse'."

She grinned at a sudden thought. "Here's an interesting tidbit you might enjoy. Krook dies of spontaneous human combustion."

"Get out." Bruce's eyes were wide. "Seriously?"

"When two of the other characters find his body, he's a pile of burning goo."

He shook his head. "Wow. I had no idea Dickens was so..."

"Metal?" Tegan offered.

He burst out laughing. "Yes," he agreed. "Metal."

"So let me ask _you_ a question," she said. "As the world's leading biophysicist, under what circumstances would spontaneous human combustion actually be possible?"

At the words _world's leading biophysicist_, Bruce's cheeks seemed to turn a slightly darker shade of green. "Well, combustion is essentially just an oxidation reaction - a fuel and an oxidizer reacting together to produce energy. Spontaneous combustion occurs when the external temperature of an object is so low that its internal heat can't be dissipated. Instead it continues to increase, until the object bursts into flames. This happens all the time. If a pile of straw or sawdust or oily rags gets hot enough, it'll catch on fire. Even without the introduction of an outside heat source."

He became more animated as he spoke, obviously enjoying the topic. His hands weaved expressive patterns in the air, and his eyes were positively sparkling. Tegan found it unexpectedly endearing.

"So why don't people catch on fire?" she asked.

He gave a wry smile. "Because our bodies are homeothermic," he told her. "Constant metabolic processes keep us at a steady internal temperature. In order for a person to ignite from within, their internal temperature would have to reach well over a thousand degrees Celsius, and they would die long before that happened."

"And once a person dies, those metabolic processes stop, as well," said Tegan, "which would cause their temperature to drop again."

"Exactly."

"So it's not possible."

Bruce inclined his head. "As a scientist, I can't say that for certain," he replied reluctantly. "Until it has been definitely proven impossible, it can't be ruled out. I mean, look at me. Technically, _I_ shouldn't be possible, but here I stand."

Tegan couldn't argue with that. But the thought only served to spark her curiosity even further. "If you don't mind my asking," she said carefully, "how exactly _did_ you do... this?" She gestured vaguely to his substantial person. "Combine Bruce Banner and the Hulk, I mean."

He blew out a breath, generating enough force to stir Tegan's hair slightly. "It's, uhh... insanely complicated," he said. "To explain it fully, I'd have to go into the whole process of molecular decay and gamma emissions, and I've already kept you way too long. The long and short of it is that I managed, using a combination of a specialized serum and several concentrated bursts of radiation, to trigger the chemical reactions that occur when I transform into the Hulk, and then _arrest_ them in mid-transformation. So I was able to retain my - or, rather, Banner's - personality, while also allowing the Hulk's to surface, as well."

"That's... incredible," she breathed. Then she winced as she realized what she'd said. "Sorry."

He smiled. "It's okay."

She returned his smile. "So how much of you is Bruce Banner, and how much is the Hulk?"

He ran a hand through his greying hair. "I'd say it's about fifty-fifty. I've got Banner's intelligence and rational mind, which evens out the Hulk's temper, and Hulk's confidence and charisma, which makes up for Banner's anxieties and... social ineptitude. And, of course," he added, "Hulk's Olympian physique." He was unable to keep a straight face as he said this.

"Don't forget his modesty," Tegan pointed out jokingly.

He scrunched up his face. "I _am_ kind of an asshole now."

She laughed.

Eventually, every last book was returned to its proper place. Bruce looked around the shop, nodding in approval. "Looks good," he decided. "It's almost as if a big, clumsy, green behemoth never blundered in and trashed the place."

Tegan gave a casual shrug. "Those books needed reorganizing, anyway."

His eyes slipped shut. "Ah, yes. Soothe me with sweet lies."

She laughed again. "Well, regardless of what exactly precipitated the, umm... _precipitation_ of books," she said with a grin, "I still had a good time. Thanks for your help. And for the doughnuts."

"It was my pleasure," he replied sincerely. "And please, keep the leftovers." He hesitated for a moment. "I guess I should get out of your hair."

Her smile faded. "Right."

Despite the sense of satisfaction it brought Tegan to see order restored to her father's beloved book shop, it also filled her with an another emotion: disappointment. The work was done. And although it was true that Bruce had made the work necessary in the first place, she had genuinely enjoyed their time together. Lately, it had seemed to Tegan like she had been stagnating. Every day, she came downstairs, sorted books, helped the occasional customer, and went back upstairs, only to repeat the whole process the next day. There was no variety. But Bruce Banner's sudden reappearance in her life had woken something in her that had lain dormant for too long - the desire to connect with another person, to learn more about them, to get to know them better. And, just maybe, to let them get to know her.

Now there was nothing keeping Bruce from ever coming back.

Unless...

She blurted it out just as he was turning toward the door: "Bruce!"

He paused, blinking at her. "Yes?"

_God, I'm an idiot,_ she thought, feeling her face grow warm. Nevertheless, she forced herself to go on. "I don't know if you saw the sign on the door, but there's a book club that meets here on Thursday nights. Right now we have about half a dozen people who come regularly. It's a lot of fun. We're starting a new book this week. It's called _Wind, Sand, and Stars_ by Antoine de Saint-Exupéry."

She was all too aware that she was babbling. However, Bruce narrowed his eyes in thought. "Why do I know that name?" he asked.

"I'm probably butchering it horribly-"

"No, no, I mean, it sounds familiar. He wrote something else, didn't he? Something famous?"

"_The Little Prince_," said Tegan.

"That's right," he murmured.

"This other book is a memoir about his experiences as a pilot for the airmail carrier Aéropostale. He went through some pretty intense stuff. I think you'd like it." She cleared her throat. "Anyway, if you're interested, we meet at six."

To his credit, Bruce seriously seemed to consider it. "I'll think about it," he said.

"Sure, no pressure," she told him, trying to sound indifferent and failing miserably. "It was great seeing you again, Bruce."

He smiled. "Yeah, same here," he replied, engulfing her hand in his one last time. "Take care... Tegan."

She forced herself to return his smile. "You, too."

As she watched him leave, Tegan felt her shoulder start to ache again. Strange; it hadn't given her any trouble all day.

She turned away, shaking her head. What had she been thinking, inviting Dr. Bruce Banner to her book club? He was one of the smartest people on the planet, certainly the smartest in his chosen fields of science. No doubt he had far better things to do than read a book in which he had no interest, and then discuss it with a group of total strangers. More than likely, she would never see him again.

The thought saddened her more than she would have expected.

She heard the door open again, and she turned to see Bruce in the doorway, his huge form blocking out the late afternoon September sun.

"Do you have any copies of that book left?" he asked.

A sudden, strange warmth ignited in Tegan's chest and seemed to spread outward. If she didn't know better, she might have attributed it to spontaneous human combustion.

"I think I have one or two," she said.

* * *

**Author's Note:** Okay, so I don't have the slightest clue how Bruce merged his two personalities, and it isn't explained in _Endgame_, so I freely admit that I BSed my way through his explanation. I hope it made some sense. Review and let me know if it sounded okay to you. And also if I should continue this story. Thanks!


	4. Four: Synchronizing Brainwaves

**Author's Note:** My thanks for all the faves, follows, and reviews. I guess I'll keep writing. Enjoy the latest chapter!

* * *

**The Formula for Change**

Four: Synchronizing Brainwaves

It wasn't until she had watched Bruce leave with his newly-purchased copy of _Wind, Sand, and Stars_ that Tegan fully realized what she'd done. Though the chances were probably low that he would actually attend the book club meeting on Thursday, it was at any rate a possibility. As she tried envisioning the reaction of the various other members of the club upon seeing the Hulk show up at the book store, the results were mixed, at best. Some of them would be excited or intrigued. One or two others might be alarmed. In view of the way the world had treated the Hulk in the past, it would be unkind to introduce Bruce to an environment in which he might not be well-received.

The only course of action was to notify the club in advance. Forewarned was forearmed, as the old adage went.

Retrieving her phone from her pocket, Tegan opened her messaging app and pulled up the book club's group chat. After a moment's deliberation, she had composed her message:

_Hey, gang, just a head's up. We might possibly have a new addition to our group this week._

_Not cryptic or ambiguous at all_, she thought dryly, shaking her head. Taking a deep breath, she hit 'send'.

She flipped the sign on the door to 'Open', indicating that the shop was once again ready to receive customers. Not that it had been a bustling business before, by any means. Most of the shops in the area had suffered from the effects of the drastically reduced population. Aside from the liquor store down the street, of course.

Not much time passed before she received the first reply to her text. It was from Becky, one of a pair of teenaged twins, the youngest members of the book club.

_Did you get another cat?_

Tegan snorted and texted back:

_You're hilarious. And no. It's a person._

The next text came from Sameer, a man who lived nearby, and was around the same age as Tegan:

_You're being annoyingly vague, Tegan. Which tells me that it's most likely someone from your days of elbow-rubbing with celebrities._

She narrowed her eyes. Damn him, he was far too astute. With a smirk, she replied:

_Signs point to yes._

Within seconds, her phone exploded.

_So who is it?_

_Out with it, lady._

_OMG! Is it an Avenger? It's Captain America, isn't it?_

Laughing under her breath, Tegan decided she had held the others in suspense long enough.

_Close, Becky. It's Bruce Banner._

Becky's response was immediate:

_Whaaaaaaaaaaattttt?_

The reply from Max, the group's eldest member, was less enthusiastic.

_I don't know about that._

Tegan frowned.

_What do you mean, Max? Do you think I'm joking? Because for once, I'm being very serious._

His answer did not come immediately. When it did, Tegan's frown only deepened.

_I'm just not sure that's a very good idea. That man does not seem stable to me._

She wasn't quite sure what to say to this. Two days ago, she might have agreed with Max's assessment of Bruce Banner. But that was before meeting 'Professor Hulk', as his students called him. He seemed perfectly stable to her; at least, as stable as a person who had performed radical scientific experiments on himself could be. Then again, she had not always been the best judge of character in the past. And Max knew that quite well.

At the same time, Tegan couldn't forget Bruce's demeanor when he had interacted with her, and Jamie. He had been relaxed, easy-going; in fact, he had possessed a kind of Zen, almost Yoda-like calm that was genuinely pleasant to be around. It was a jarring contrast from the nervous, guarded manner he'd displayed on their first meeting.

Somehow she knew, on a deep, visceral level she couldn't explain, that she had nothing to fear from him. It was not a feeling she was accustomed to having.

Very carefully, she composed her response, reading it back to herself more than once before sending it:

_I understand your concern, Max. But his circumstances have changed drastically. He's not at odds with his alter-ego anymore. He's at peace with himself now. In fact, he's teaching at Harvard. It's hard to explain, and you won't fully understand until you meet him, but I can personally vouch for him. He's not a danger to anyone._

A moment later, her text was answered by Pearl, the second eldest member of the club:

_Who are you talking about?_

Sameer replied before Tegan got the chance:

_Scroll up, Pearl._

There was a pause, in which the entire group seemed to wait. And then:

_Who is Bruce Banner? Is that the fellow who's a lady now?_

"Oh, my God, Pearl," Tegan blurted aloud, covering her mouth to stifle a laugh.

While she tried to recover, Becky's twin sister Hailey responded:

_That's Bruce Jenner, Pearl. Bruce Banner is the Hulk. The big green dude._

A few seconds later, Pearl replied with a string of texts, in quick succession:

_Oh!_

_Okay then, that's fine._

_But for the record, it would have been fine if it was Bruce Jenner, too._

_I mean Caitlyn._

Tegan laughed again, shaking her head. And then she smiled as she read Max's text, couched in his usual thoughtful, well-worded manner:

_Fair enough, Tea. I trust your judgment. You've grown a lot over the years, and if you say Dr. Banner is all right, I'll take your word for it. I just hope he knows what he's getting himself into. We're one singularly anal, pedantic bunch._

Rolling her eyes good-naturedly, she texted back:

_He's a Harvard professor. I'm pretty sure he's used to pedantic. But thanks, Max. Of course, he probably won't show up anyway, which makes all of this speculation totally pointless._

To this Sameer texted:

_That's the spirit!_

At that moment, a group of customers walked through the door. Putting her phone away, Tegan greeted them and invited them to let her know if they needed help finding anything. As they began to mill around the shop, her phone buzzed again. Sighing, she took it out and unlocked it. Then she chuckled as she read Becky's text.

_So is he bringing Captain America with him?_

* * *

In his office in the historic Jefferson Building at 17 Oxford Street, Bruce Banner sat at his large mahogany desk, going over his lecture notes. The desk had come with the office, but the chair was a more recent addition, a custom-made construction of factory-grade steel and carbon fiber-reinforced polymer. It had, in fact, been designed by one of his fellow professors in the Engineering Department — free of charge, unlike most of the furniture in his home in east Cambridge. Though he had no regrets about merging his fractured personalities, he had to admit there had been distinct advantages to being "puny Banner".

The day had passed slowly, which was not unusual. Bruce only taught one class on Thursdays, and it was held in the morning. He typically spent his afternoons preparing and rehearsing lectures, grading the quizzes and lab work he had assigned his students, and brushing up on the latest breakthroughs in various scientific fields. Today, however, he was a bit distracted. There was something that was preventing him from focusing on his notes, and he was fairly certain he knew what it was.

On his desk, among piles of research papers and reference books, the corner of a slim paperback peeked out at him, as if reproaching him for being ignored. With a sigh, he drew it out and began leafing through it. The first chapter was not long; only twenty pages. It wouldn't take more than a few minutes to read.

So why couldn't he bring himself to do it?

It wasn't that the subject matter was uninteresting to him. Although he rarely read for pleasure anymore, and what he did read was usually related to his own fields of research, he still liked to branch out. And the book itself was evidently universally adored; _National Geographic_ had even listed it as one of the top ten adventure books of all time. He supposed, if he was being completely honest with himself, he knew on some level that as long as he put off reading it, he would have a reason not to go to the book club meeting. Once he read it, he would have no excuse.

On the one hand, Bruce did want to see Tegan Thomas again. Very much. He could admit that. He had enjoyed getting reacquainted with her the previous weekend, as he helped her clean up the disaster he'd made of her shop. On the other hand, it would be pointless to deny that he had been attracted to her. Tegan was sweet, funny, intelligent, distractingly pretty, and extremely forgiving of his flaws. But she was also quite a bit younger than him, and he'd already made that mistake with Natasha. And of course, there was the not-so-little matter of his appearance. He was fully aware of what he looked like, and it was safe to say that his dating days were over. That ship had not only sailed, but capsized, as well.

Then again, Tegan had seemed pleased when he told her he would consider attending the book club. He didn't want to disappoint her. But perhaps she was just being friendly. She might not care either way.

He growled and threw the book onto his desk again with more force than he'd intended, causing more books and papers to slide off onto the floor. Not for the first time, he cursed his avoidant tendencies. Though indecisiveness and timidity had never been aspects of the Hulk's personality, they were traits which Bruce Banner had always had in spades, and on occasion, they still got the better of him. He wouldn't have minded much if the Hulk had smashed those parts of him permanently.

Suddenly he heard a knock and looked up to see Spencer Hay, an astronomy professor whose office was down the hall, standing in his open doorway. He took in the mess on the floor with an amused smirk. "Your lecture isn't _that_ bad, is it?" he asked.

Bruce sighed and stood up. "Oh, the lecture's fine," he replied dryly, stepping out from behind his desk to pick up the books and papers. "The lecturer, on the other hand, is what the kids call a 'hot mess'."

"Everything all right, Banner?" Hay inquired as he helped retrieve the scattered items.

He didn't answer directly. He was remembering something he'd read recently. "How many friends do you have on social media?"

"Markedly fewer than I did a few years ago."

Bruce rolled his eyes. "Seriously, how many?"

Hay stroked his beard thoughtfully for a moment. "I don't know. A hundred."

"I have like... thirty. And I'm not sure I'd call most of them 'friends'. More like, people who guilted me into accepting their requests." He shook his head and went on. "According to Dunbar's number theory, the limit to the number of people with whom an individual can realistically maintain a stable social relationship is one hundred and fifty. Before the Decimation, the average number of friends a Facebook user had was three hundred and thirty-eight. Note the disparity."

"Quite," Hay agreed. "What brought this up?"

Bruce started to lean against his desk, then thought better of it. "It was just something I came across the other day — a study on how the brain is negatively affected by social media. It goes without saying that friendship has a positive affect on the brain. It promotes the formation of new connections between neurons, and protects against the effects of dementia."

"Sure..."

"But the brain also influences _who_ we become friends with," Bruce continued. "Did you know that brainwaves are significantly more similar between friends than between strangers? Dr. Carolyn Parkinson of the University of California performed an experiment using forty-two graduate students, who were all acquainted with each other to varying degrees. Her team hooked them up to fMRI devices that tracked blood flow to their brains as they watched a number of video clips: some physical comedy, an astronaut pouring water in low gravity, a terrible music video. The researchers found that the more closely two subjects were acquainted, the more their brains shared a pattern concordance in the way they reacted to stimuli. Close friends showed the same spikes in attention, distraction, peaks in the reward processes, and so on."

Hay frowned. "So what does that mean?"

"It means," he explained, "that the reasons behind friendship are more than just similarities in background, tastes, and temperament. It's deeper than that. It goes down to the very structure of our brains, and the way they process the world around us. It's why two people who have never met before can 'click' instantly. And it also means that the superficial relationships we forge on social media can never achieve real depth or meaning. An occasional comment or a 'like' can't replace direct human interaction, because that 'meeting of minds' can't occur. There's no... pattern concordance, no synchronizing brainwaves. _That's_ what makes a friendship."

"You're like Bill Nye and Mister Rogers all rolled into one," said Hay jokingly. "Why are you telling me all this?"

Bruce shook his head, running a hand through his salt-and-pepper hair. "Because I'm trying to decide if I should join a book club."

The astronomy professor raised his eyebrows. "A book club?" he repeated in surprise. "I didn't know those were still around. How did this happen?"

Bruce turned away to straighten some papers on his desk. "I... met someone," he said, less casually than he would have liked. "_Re_-met her, actually. She used to work for Tony Stark. I briefly made her acquaintance once, six years ago."

"Is she single?"

"I have no idea, and frankly, it's not relevant," he said firmly. "She owns a book shop, I walked into said book shop, and there she was. So she invited me to join her club. That's all."

Hay snorted. "Okay," he replied, sounding unconvinced. "So what book are you reading?"

In answer, Bruce picked up his copy of _Wind, Sand, and Stars_ from his desk and tossed it to him.

The other man caught it and read the cover. "This is a good book," he said, nodding in approval.

"So I hear," said Bruce. "I haven't started it yet."

"And when's the next meeting?"

"Tonight." He winced.

"And you haven't started?" Hay asked incredulously. "What the hell, Banner?"

Bruce sighed. "I told you. I'm... undecided."

Hay set down the book and folded his arms over his chest. "No offense, but for someone who just got done touting the benefits of friendship on the brain, you don't seem to have much of a social life," he said. "You've been in Boston, what, two months? And yet I've never seen you socialize with anyone outside of work. Now out of nowhere, you run into this woman, this... What's her name?"

"Tegan," he murmured.

"Tegan. So you meet her once, and then six years later, you just happen to walk into her book shop. I don't need to tell you that the odds of that happening are statistically significant. I'm assuming you find her attractive, otherwise you wouldn't be feeling conflicted about seeing her again."

"That's not—"

"Not relevant?" Hay asked dubiously. "Fine. Have it your way. But I still think you should go. Make some new friends. Get to know this Tegan. Treat it as an experiment if you want, to find out if your brainwaves match up." Suddenly he grinned. "If you don't go, then you have to come to O'Shea's with the other astronomy professors and me. It's cheap drink night. Two-dollar whiskey shots. Although with your status as a former Avenger, you can probably get them for free."

"That seems spectacularly ill-advised," Bruce remarked dryly.

"They've got to get rid of all that bottom-shelf liquor somehow," Hay replied. "But those are your choices. O'Shea's, or the book club."

Wordlessly, Bruce picked up the book.

Hay chuckled. "There, was that so hard?" He reached up and slapped Bruce on his massive arm. "Enjoy your book, Incredible Sulk."

"I like that one, that's a good one."

As Hay left, Bruce let out a long breath, staring down at the slim paperback in his hands. What was he worried about? If he decided this whole book club business wasn't for him, he would politely bow out and go back to his normal, mundane life of teaching students and signing autographs. If it did work out, he would have a reason to avoid two-dollar shots night at O'Shea's. And he might possibly gain a friend or two.

He remembered the easy, comfortable rapport he and Tegan had built as they'd put the fallen books back on the shelves. He was so used to being treated like either a celebrity, an academic, a scientist, or an oddity, he had nearly forgotten what it was like to be around someone who treated him like a person. He had felt relaxed around Tegan, free to be himself. He hadn't realized how much he had missed that feeling.

He thought of the way Tegan's hazel eyes had lit up when he had asked her for a copy of _Wind, Sand, and Stars_. She had seemed genuinely pleased. Almost... excited.

Slowly, almost without conscious thought, he sat down and opened the book to the first chapter. Leaning back in his chair, he began to read.

* * *

Tegan didn't know what she was going to do if Bruce Banner showed up tonight. She had no place for him to sit.

She had no idea how much Bruce actually weighed, and even if it had occurred to her to ask him earlier, it would have been far too rude to do so. But she was reasonably certain that none of the chairs she owned were sturdy enough to hold him. So she had called every furniture store in Boston, hoping to find one which sold high weight capacity chairs. To be on the safe side, she had specifically requested anything able to hold up to 1,200 pounds. Needless to say, she hadn't had any success.

Finally, after a lengthy Internet search, she had found a company that made furniture for hospital waiting rooms, including chairs designed to withstand up to 2,000 pounds. She had even asked the sales representative point-blank if the chair was strong enough to hold the Hulk, and had received a confident answer in the affirmative. The only problem was that the chairs were custom made in Wisconsin, and would take several weeks to arrive. Which left her back at square one.

She really hadn't thought this through.

Unfortunately, it was too late to worry about it now.

As Tegan finished arranging the chairs and setting out the snacks and drinks, the first member of the book club showed up: Pearl Castillo, a woman in her late sixties whose dyed auburn hair was always perfectly arranged. As usual, she had brought a phenomenal example of her baking skills. As she set down the plate of almond cookies, she made a show of looking around the shop.

"Is your friend here yet?" she asked curiously.

Tegan shook her head. "No, and I told you not to get your hopes up," she said. "He's a world-renowned physicist. I'm sure he has plenty of other demands on his time."

"Well, genius or not, if he says no to you, he's an idiot," Pearl told her firmly as she settled in her customary seat.

The twins, Becky and Hailey Chen, were the next to arrive. Hailey, as the more reserved of the pair, was relatively calm over the prospect of the possible visitor, but Becky made no attempt to hide her excitement. As she plied Tegan with questions, she bounced in place on the balls of her feet until she was all but ordered to sit down.

Sameer Samadhi was next, still wearing medical scrubs from his job as a technician at a nearby dental practice. He hadn't had time to change, for which he was profoundly apologetic. And yet he had no compunctions about immediately helping himself to the refreshments.

Last to arrive was Max Lowry, a long-time friend of Tegan's late father. He greeted her with a kiss on the cheek and a bag of Cheetos which had already been opened.

And just like that, it was six o'clock, and there was no sign of Bruce Banner. Tegan tried her best to shrug it off, but it was surprisingly difficult not to let her disappointment show. Despite her admonitions to the others, she had really hoped she would see him again.

"All right, gang," she said, moving to take her seat, "let's get started. How did everyone like the first—"

She broke off abruptly as the door opened, and Bruce stepped through, filling the doorframe with his huge body.

"Oh, _damn_," Becky whispered, eyes wide.

"Bruce," Tegan exclaimed, rising to her feet with a smile she couldn't seem to contain. "Glad you could make it."

"Thanks," he replied. "Sorry, I know I'm cutting it close. I had to stop at my house to get a chair." He stepped inside as he spoke, carrying a large, sturdy-looking folding chair in one hand. "As forgiving as you were when I knocked all your book shelves over, I wasn't sure you'd be as lenient if I destroyed your furniture."

Relief flooded through Tegan at the sight of it. "At least you had the prescience to think of it," she said. "I scoured all of Boston for a Hulk-sized chair, and I couldn't find anything."

Bruce smiled wryly. "That was very considerate of you, but I would have been fine on the floor."

"Thankfully, that won't be necessary. Please, have a seat anywhere."

As he found a place to set down his chair, Tegan realized the others were staring openly at him. "Why don't I make the introductions?" she suggested hastily. "Bruce, this is Max Lowry, Pearl Castillo, Hailey and Becky Chen, and Sameer Samadhi. Everyone, I'd like you to meet Bruce Banner."

"Pleased to meet you all," said Bruce with a nod.

There was a brief, awkward silence. And then Sameer stood up and offered Bruce his hand. "It's an honor to meet you, Dr. Banner," he said sincerely. "I read all about your work in sub-Saharan Africa. That affordable, efficient water purification system you developed saved a lot of lives. That was... very cool."

"Well, thank you... Sameer, was it?" he asked. "I'm glad I was able to help. After I trashed Johannesburg, I figured it was the least I could do for the continent."

Pearl rose and greeted him as well. "Hi, I'm Pearl. May I just say, I don't know what you did, but..." She gestured shamelessly toward his expansive shoulders. "I love your new look."

"Thank you," Bruce said with a chuckle. "And please, call me Bruce. That goes for everyone."

The twins were next to introduce themselves, which they did in their usual friendly, effusive way. Finally Max rose from his chair and shook the man's hand, welcoming him to the group in his quiet, unassuming voice. Tegan ducked her head, allowing the curtain of her hair to hide her smile. She had been concerned that Bruce might not be warmly received, but apparently she had been worrying over nothing. She should have known better than to doubt these people.

As everyone settled in their seats, she cleared her throat. "All right, let's get into it," she said. "This is everyone's first time reading _Wind, Sand, and Stars_, which means it will be a new experience for all of us. So. Chapter One: 'The Craft'. What were everyone's initial impressions?"

The others looked at each other a moment, until Pearl gave a shrug. "Oh, I'll go first," she said. "I really enjoy the author's style of writing so far. I mean, I know it's translated from French, but still... He has a depth and almost poetic quality to his narration that I wouldn't have expected from a pilot."

"He really does," agreed Becky. "I loved the way he described flying as 'the frontier between the real and the unreal, the knowable and the unknowable.' Or here on the second page: 'Black dragons guarded the mouths of the valleys, and clusters of lightning crowned the crests.' I never realized how dangerous it was to be a pilot back then. It was almost expected for them to hear of others who had been lost or killed."

"I know," said her sister Hailey. "That story about how he got lost at night over the Sahara was terrifying. Back then, nothing in those planes was automated. I can't imagine flying blind in the dark, running low on fuel, while trying to find the single light in the desert that meant you were in the right place."

"By the way, did you know that the author was a big influence on Miyazaki's work?" Becky asked.

Pearl frowned. "Miya-who?"

"Hayao Miyazaki. He's a Japanese film-maker." The girl sighed, her shoulders slumping. "Or, he _was_."

Sameer was nodding. "I can definitely see where he got his inspiration," he said. "Miyazaki's films seem to romanticize aviation, especially _The Wind Rises_. There's that same sense of wonder and adventure in this book. At least, what we've read so far."

"I thought the author came across as a little arrogant," Max remarked.

Tegan turned to him. "How so, Max?"

The older man leaned back in his chair, pausing as if to consider his next words. "He seemed to think of himself as a hero charged with this grand, noble task of delivering airmail, and he looked down on all the ordinary people with their mundane jobs and their 'monotonous lives'." He shook his head. "The thing is, though, this guy was born a wealthy aristrocrat who had the luxury to pursue his dreams. Not everyone is that fortunate. That doesn't make their lives any less important."

Bruce, who had been quiet so far, suddenly made a wordless noise of dissent. "Mmm..."

"Yes, Bruce?" Tegan prompted.

He blinked, caught off guard. "Oh, no, nothing. I'm sorry, sir. You were still talking."

Max waved his hand. "No, please."

Bruce hesitated. "With all due respect, I can understand how you would come to that conclusion," he told Max. "But I didn't see it that way. To me, it was like he was lamenting the fact that the unavoidable, mundane things in life tend to have a destructive impact on the creative spirit. We get so wrapped up in our day-to-day problems that we forget to ask more of ourselves. After a while, we just... give up."

"That's what I got out of it, too," said Tegan. "So many of us struggle so hard just to get through life that we forget to _live_."

Bruce caught her eye and smiled.

"Maybe we should all take flying lessons," Sameer jokingly suggested, making everyone chuckle.

"Already been there," Bruce replied dryly. "I think I'll pass on that one."

The others laughed again, and Tegan smiled to herself as the conversation continued.

* * *

Bruce felt as if he were dreaming. He watched as Sameer, the young Indian man with the English accent, pretended to point out a stain on Becky Chen's blouse. Of course, she looked down, and hit him when she realized she'd fallen for the joke. Meanwhile her sister Hailey was talking with the older woman, Pearl, showing her how to update the e-reader app on her phone. And Tegan Thomas was deep in conversation with Max, the older gentleman who looked like he could be Elliot Gould's understudy.

He was surrounded by people of drastically varying ages, backgrounds, and personalities, and yet they were perfectly at ease with each other. What was more, they also seemed at ease with _him_. After the book discussion had ended, Sameer immediately asked Bruce about his classes at Harvard, as well as any research he was conducting on his own. The twins insisted on making him try the desserts they'd each brought and judge the winner. (To their annoyance, he had declared it a draw.) And Pearl just kept finding excuses to touch him.

Tegan noticed him observing her and drifted over to him, a mug of tea in her hand. "Well," she said, "what did you think?"

Bruce found himself struggling to put his impressions into words. "This was... nice," he said at last, rather lamely. "It was a nice experience. The book itself isn't the sort of thing I usually read, but that's a good thing. It's a refreshing change."

She nodded, as if satisfied with his answer. "And will we be seeing you as a regular attendee?"

He looked down at her as she sipped her tea in an overly casual manner, noticing for the first time the smattering of freckles that dusted her nose. For some reason, he really liked that. Feeling rather reckless, he found himself saying, "Throw in some more of Pearl's almond cookies, and we've got a deal."

Overhearing his remark, Pearl practically beamed with pleasure. "This one's a keeper," she said to Tegan, reaching up and patting Bruce's arm. Then, to his surprise, she squeezed his bicep. "Holy Moses," she muttered.

As she drifted off to sample the refreshments, Bruce turned back to Tegan. She was clearly mortified, but trying not to laugh. "Sorry," she whispered.

Bruce gave a shrug. "Don't worry about it," he replied. "I can't help being the biggest and the strongest. I don't even exercise."

She whipped her head toward him, her mouth slightly open. "Did you just quote Fezzik from _The Princess Bride_?"

He merely shrugged again, and she laughed. "Excuse me for a moment," she said. "I have to go talk to Pearl about sexual harassment."

Bruce watched her move away, smiling absently to himself. At that moment Max came over, a cup of coffee in his hand. "So, Bruce," he said conversationally. "Tell me how you and Tegan know each other."

"Well, I knocked all her book cases over, but before that, we actually met at Avengers Tower. This was before Sokovia, before I..." He gave a self-deprecating smirk. "Before I went on a field trip."

"You mean when you left Earth?" Max asked.

"Yeah."

"That was a hell of a thing. I'll bet you're glad to be back."

Bruce paused, considering the question. "Yes and no," he replied at last. "The Hulk liked Sakaar, but Banner was not a fan."

"But now you're both."

"I've always been both. Well, not _always_," he amended. "For a long time. Since..."

He cut himself off abruptly. He had almost said, _Since I was a kid._ But there was no point in getting into that. This man didn't need to know his life story. And Bruce was certainly in no hurry to give it to him.

He cleared his throat. "Anyway, I've just never been both at the same time," he said. Eager to change the subject, he asked, "How long have you known her? Tegan, I mean."

"Oh, I've known Tegan since she was a little girl," Max told him. "Her father and I were good friends. Back in the eighties, it wasn't very common for a black man to be a business owner around here. For that matter, it wasn't all that common for a black man to be married to a white woman. So when Nathaniel Thomas moved into the area and opened up a book shop with his white wife and two biracial children, he didn't exactly get the warmest reception." He shook his head. "But that sort of thing never mattered to me. So my wife and I welcomed them to the neighborhood, bought a few books. Bought a _lot_ of books. And we were friends from then on."

Bruce smiled. "He was fortunate to have a friend like you."

"I was the fortunate one," said Max. "He was a good man. And I got to watch his kids grow up. My wife and I couldn't have any of our own."

"I'm sorry," Bruce said quietly.

Max didn't appear to hear him. He was watching Tegan, who was laughing at something Sameer had told her. "Tegan is an amazingly strong woman," he said. "She's endured a lot. She lost her parents, her brother."

"Her fiancé," Bruce murmured.

Max glanced up at him sharply. "You know about him?"

Bruce felt his eyebrows climb upward, and he began to stammer. "Uhhh... Not... really, I... She only told me he died in the Decimation."

The older man nodded, looking away again. "Yeah," he muttered. "One of the few good things to come out of that God-awful day."

His remark surprised Bruce. "You didn't care for him?" he asked.

Max's answer did not come immediately. "I don't care for anyone who hurts Tegan," he said evenly.

A silence fell between them, which Bruce had no idea how to break. At last Max heaved a sigh which conveyed an air of finality. "Anyway. Good to meet you, Bruce."

"Likewise," he said vaguely, frowning after him.

The evening began to wind down, and one by one the members of the book club trickled out. Bruce lingered behind, assisting Tegan in collecting the dirty dishes and putting the chairs in the supply closet. He was strangely reluctant to leave. It was not even eight o'clock, and he found he wasn't ready for the evening to be over yet. He hadn't realized how much he had missed simple human interaction. Speaking in front of a lecture hall full of students just wasn't the same. And although part of him had always been an introvert and a bit of a recluse, the Hulk half of him had only ever wanted to be accepted.

Both halves of him had felt accepted here.

"Thanks for helping with the clean-up," Tegan was saying as she walked with him to the door.

"No problem," he replied. "Thank you for inviting me. To be honest, I wasn't totally sure if the whole 'book club' thing was for me, but... I'm really glad I came."

"That's what she said," Tegan mumbled absently.

Bruce stared at her for a moment in disbelief, before bursting out laughing.

Realizing what she'd said, she gasped and clamped a hand over her mouth. "Oh, my God," she blurted, her words muffled. She drew her hand away. "I'm so sorry. Hannah and I say that to each other all the time, but... I guess I just forgot that you and I barely know each other."

"Well, I'm flattered you feel comfortable enough around me to make wildly inappropriate jokes," he said, still chuckling.

She groaned and buried her face in her hands, and Bruce patted her shoulder reassuringly. "Don't worry about it," he told her. "It was funny." He arched an inquiring eyebrow. "So, same time next week?"

Tegan looked up at him and smiled. "I'll be here."

"Is it all right if I leave my chair?"

"Of course!"

"Great." Aware that he was stalling, he held his hand out toward her. "Good night, Tegan."

Without a trace of hesitation, she placed her tiny hand in his. "Good night," she said kindly.

With a strangely warm, light sensation building in his chest, Bruce turned and stepped out of the shop and into the cool night air. As he began to make his way to his vehicle, which was parked down the street, he suddenly heard Tegan's voice call out behind him.

"Bruce?"

He turned back toward her. "Yes?"

"Rest well, and dream of large women."

Bruce shook his head, laughing all the way to his car.

* * *

**Author's Note:** Sorry I killed off Miyazaki. It's only for pretend. Out of curiosity, has anyone read _Wind, Sand, and Stars_? It really is a wonderful book. Anyway, let me know what you think so far!


End file.
